Method and system for highlighting modified content in a shared document

ABSTRACT

A shared document is displayed in a customized form with highlighted content that identifies significant portions of the document. The highlighted content draws a user&#39;s attention to the portions of the document that may have been modified, deleted or added by others since the last time the user accessed the document. The highlighted content directs a user to modified document portions that the user has not yet read.

BACKGROUND OF THE INVENTION

Shared document applications allow several different users tocollectively share information. For example, many users may access thesame document to add information to a shared research notebook. Changesmade to the document may be shown as tracked changes that indicatemodification details. All document changes are stored in the same filebecause the same document view is provided to all users that access theshared document. A user may access the shared document and be presentedwith a history of modifications, additions, and deletions made to thedocument. However, the tracked changes may provide a cluttered view ofthe document because the changes remain visible to the user even if theuser has previously read the modified document portions.

SUMMARY OF THE INVENTION

The present invention is directed to a method and system forhighlighting modified content in a shared document. A shared document isdisplayed in a customized form with highlighted content that identifiessignificant portions of the document. The highlighted content draws auser's attention to the portions of the document that may have beenmodified, deleted or added by others since the last time the useraccessed the document. The highlighted content directs a user tomodified document portions that the user has not yet read.

In one aspect of the invention, a document is downloaded to a clientfrom a server. A determination is made whether content in the documenthas been modified since a previous download. The content that has beenmodified since the previous download is highlighted. The document isthen displayed at the client.

In another aspect of the invention, a system for highlighting modifiedcontent in a shared document includes a server, an editor client coupledto the server, a reader client coupled to the server, and a modificationhighlight module that is located on the server or the reader client. Theeditor client accesses the document from the server and modifies thedocument. The reader client accesses the document from the server. Themodification highlight module highlights content that has been modifiedin the document since the document was previously accessed by the readerclient.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a computing device that may be used according to anexample embodiment of the present invention.

FIG. 2 illustrates a block diagram of a system for highlighting modifiedcontent in a shared document, in accordance with the present invention.

FIG. 3 illustrates a shared document as it appears on a display beforeand after modifications are made to document content, in accordance withthe present invention.

FIG. 4 illustrates an operational flow diagram illustrating a processfor modifying content in a shared document, in accordance with thepresent invention.

FIG. 5 illustrates an operational flow diagram illustrating a processfor highlighting modified content in a shared document, in accordancewith the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

A shared document is displayed in a customized form with highlightedcontent that identifies significant portions of the document. Thehighlighted content draws a user's attention to the portions of thedocument that may have been modified, deleted or added by others sincethe last time the user accessed the document. The highlighted contentdirects a user to modified document portions that the user has not yetread.

Illustrative Operating Environment

With reference to FIG. 1, one example system for implementing theinvention includes a computing device, such as computing device 100.Computing device 100 may be configured as a client, a server, a mobiledevice, or any other computing device that interacts with data in anetwork based collaboration system. In a very basic configuration,computing device 100 typically includes at least one processing unit 102and system memory 104. Depending on the exact configuration and type ofcomputing device, system memory 104 may be volatile (such as RAM),non-volatile (such as ROM, flash memory, etc.) or some combination ofthe two. System memory 104 typically includes an operating system 105,one or more applications 106, and may include program data 107. Amodification highlight module 108, which is described in detail below,is implemented within applications 106.

Computing device 100 may have additional features or functionality. Forexample, computing device 100 may also include additional data storagedevices (removable and/or non-removable) such as, for example, magneticdisks, optical disks, or tape. Such additional storage is illustrated inFIG. 1 by removable storage 109 and non-removable storage 110. Computerstorage media may include volatile and nonvolatile, removable andnon-removable media implemented in any method or technology for storageof information, such as computer readable instructions, data structures,program modules, or other data. System memory 104, removable storage 109and non-removable storage 110 are all examples of computer storagemedia. Computer storage media includes, but is not limited to, RAM, ROM,EEPROM, flash memory or other memory technology, CD-ROM, digitalversatile disks (DVD) or other optical storage, magnetic cassettes,magnetic tape, magnetic disk storage or other magnetic storage devices,or any other medium which can be used to store the desired informationand which can be accessed by computing device 100. Any such computerstorage media may be part of device 100. Computing device 100 may alsohave input device(s) 112 such as keyboard, mouse, pen, voice inputdevice, touch input device, etc. Output device(s) 114 such as a display,speakers, printer, etc. may also be included.

Computing device 100 also contains communication connections 116 thatallow the device to communicate with other computing devices 118, suchas over a network. Networks include local area networks and wide areanetworks, as well as other large scale networks including, but notlimited to, intranets and extranets. Communication connection 116 is oneexample of communication media. Communication media may typically beembodied by computer readable instructions, data structures, programmodules, or other data in a modulated data signal, such as a carrierwave or other transport mechanism, and includes any information deliverymedia. The term “modulated data signal” means a signal that has one ormore of its characteristics set or changed in such a manner as to encodeinformation in the signal. By way of example, and not limitation,communication media includes wired media such as a wired network ordirect-wired connection, and wireless media such as acoustic, RF,infrared and other wireless media. The term computer readable media asused herein includes both storage media and communication media.

Highlighting Modified Content in a Shared Document

FIG. 2 illustrates a block diagram of a system for highlighting modifiedcontent in a shared document. The system includes server 200,author/editor clients 250, 252, 254, and reader client 260. Server 210includes document 210 and table 220 that is associated with document210.

Document 210 is a shared document that may be accessed from server 200by clients 250, 252, 254, 260. Document 210 may be a read-only documentor otherwise unable to be changed by a user. Document 210 may bepresented to a user at reader client 260 with highlighted content thatidentifies which document portions have been modified by others but notyet read by the user. The highlighted content draws the user's attentionto the portions of the document that the user may find significant. Inone embodiment, the highlighted content may be presented in a list toprovide a user with easy access to all the modified portions of thedocument. In another embodiment, the highlighted content may be exportedto a separate file where a user may access the modified documentportions.

Document 210 includes content containers 212, 214. Each contentcontainer includes document content (e.g., a word, a sentence, aparagraph, a page, a table, a picture, handwriting, a uniform resourcelocator, or any combination of data included in document 210). Contentcontainers 212, 214 provide a dimension for document content that isgrouped together. For example, a content container may correspond to aline, a paragraph, a page, or specific page elements (e.g., only thetables on a particular page). Each content container is identified by aunique identifier (ID1, ID2).

Table 220 includes unique identifiers (ID1, ID2) that identifycorresponding content containers 212, 214. Each unique identifier isassociated with a time stamp (T2, T3). The time stamp may indicate thetime that the associated content container was created. If the contentin the content container has been modified since the content containerwas created, the time stamp indicates the time when the content in thecontent container was last modified. Modified content includes contentthat has been changed, added or deleted. In one embodiment, table 220may be updated each time document 210 is uploaded to server from clients250, 252, 254. In another embodiment, document 210 and table 220 arecontinuously updated on server 200.

Reader client 260 includes table 270. Table 270 includes uniqueidentifiers (ID1, ID2) that correspond to content containers 212, 214 indocument 210. Unique identifiers (ID1, ID2) are associated with timestamps (T1). The time stamps in table 270 indicate the time when a userat reader client 260 read the content in the content containeridentified by the unique identifier. In one embodiment, the time stampis applied when the user closes the document. Table 270 may be updatedeach time a content container is determined to have been read at readerclient 260.

Each content container is also associated with an author/editoridentifier (e.g., Author 1, Editor 1). The author/editor identifierassociates the content container with the author who created the contentcontainer or, in the case where the content in the content container hasbeen modified or deleted, the editor who last modified the content inthe content container.

An author at client 250 (e.g., Author 1) may create content containers212, 214 of document 210 at a time identified by a time stamp (e.g.,T0). The author/editor identifier (Author 1) is associated with contentcontainers 212, 214. Table 220 is updated for values of uniqueidentifiers (ID1, ID2) and time stamp (T0). A user at reader client 260may download document 210 from server 200. Document 210 is presented tothe user with highlighted content containers 212, 214 to draw the user'sattention to the newly added content that has not yet been read. In oneembodiment, the author/editor identifier associated with the contentcontainer indicates who created/modified/deleted the content. Forexample, “Author 1” may be displayed in document 210 proximate contentcontainers 212, 214. The user may read the content in content containers212, 214 at a time identified by a time stamp (e.g., T1). Time stamp T1associated with unique identifiers ID1, ID2 is updated in table 270 whenit is determined that content containers 212, 214 have been read.

An editor at client 252 (e.g., Editor 1) may download document 210 andedit content container 212 at a time identified by a timestamp (e.g.,T2). The author/editor identifier (Editor 1) is associated with contentcontainer 212. An editor at client 254 (e.g., Editor 2) may downloaddocument 210 and edit content container 214 at a time identified by atime stamp (e.g., T3). The author/editor identifier (Editor 2) isassociated with content container 214. Table 220 is updated for valuesof time stamps (T2, T3). Document 210 and table 220 are uploaded fromclients 252, 254 to server 200.

The user at reader client 260 may download document 210 from server 200.A determination is made about which content the user has not read sincethe previous download of document 210 from server 200 to reader client260. Table 270 indicates that the user at reader client 260 has notaccessed document 210 since the time identified by time stamp T1. Table220 indicates that content containers 212, 214 have both been modifiedsince the time identified by time stamp T1 because T1 identifies anearlier time than time stamps T2, T3. Thus, the user at reader client260 is determined to not have read the modified content in contentcontainers 212, 214. Document 210 is presented to the user withhighlighted content containers 212, 214 to draw the user's attention tothe newly modified content that has not yet been read. In oneembodiment, the author/editor identifier (e.g., Editor 1, Editor 2)appears in document 210 proximate the corresponding content containers212, 214 such that the user is informed about who modified thehighlighted content. The user may read the content in content containers212, 214 at a time identified by a time stamp (e.g., T4). The value oftime stamp T4 is updated in table 270 to indicate the time that the userlast read the content containers associated with the unique identifiers.Document 210 is closed and uploaded from reader client 260 to server200.

The time stamp values in table 220 remain at T2, T3 until furthermodifications, deletions or additions are made to document 210. The userat reader client 260 may access document 210 again from server 200.Document 210 is presented to the user without any highlighted contentwhen no additions, deletions or modifications have been made to document210 since the last time the user accessed document 210. In other words,a comparison of the time stamps between table 270 and table 220indicates that content in content containers 212, 214 has not beenmodified, deleted or added since the previous download of document 210from server 200 to reader client 260.

A user may not read all of the highlighted content before closingdocument 210 and uploading to server 200. For example, the user may onlyread the highlighted content identified in content container 212 withoutreading the highlighted content in content container 214. The next timethe user accesses document 210 from server 200, any content that hasbeen modified, deleted or added since the last user access ishighlighted, and the content highlighted in the previous documentversion that was not read by the user remains highlighted (e.g., contentcontainer 214).

For example, a shared document may include ten pages. An editor may makemodifications to content on pages two, five, and nine. A reader may thenaccess the document. The document presents the modifications ashighlighted content. The reader may view pages one through five beforeclosing the document. The reader may later access the document but nofurther modifications have been made to the document since the reader'slast access. The document includes highlighted content on page nine. Themodifications on pages two and five are not highlighted because thereader already viewed that content.

The user may define the feature which determines whether or nothighlighted content in a document has been read. In one embodiment, thehighlighted content is determined to have been read by the user when thepage where the highlighted content is located is displayed on a monitorof the user's computer. In another embodiment, a determination is madethat the user read the highlighted content when the entire correspondingcontent container is displayed to the user. In yet another embodiment, auser is determined to have read the highlighted content when thehighlighted content is displayed on a user interface for a predeterminedperiod of time. For example, a small content container (e.g., onesentence) may be determined to have been read when the content containerappears on the user's computer monitor for at least three seconds. Alarger content container (e.g., an entire page) may be determined tohave been read when the content container appears on a user display forat least fifteen seconds.

The locally stored table (e.g., table 270) provides the user with acustomized experience when presented with document 210 havinghighlighted content that has been modified since the previous useraccess of document 210. Two different users who access the same shareddocument at the same time may be presented with different highlightedcontent because the users previously accessed the document at differenttimes and a different amount of modifications/additions may have beenmade to the document since the previous access. For example, one usermay be presented with a document that does not include any highlightedcontent because no one modified the document since the last time theuser accessed the document. Another user may be presented withhighlighted content throughout the document because the user did notaccess the document for an extended period and several users may havemodified the document during that period.

Shared document applications are concerned with providing a repositoryfor sharing knowledge rather than displaying formal documents. Thus,maintaining a modification history is not as important as the contentadded to the document. In one embodiment, the user is not provided withan entire history of modifications that have been made to the documentsince the last user access. Rather, the user is presented withhighlighted content that indicates the latest document version at thetime the document is accessed. For example, several different changes bymany different editors may be made to the same content container in adocument between the time that the user last accessed the document andthe time of current user access. The modified content container ishighlighted in the document and includes only the most recent version.In another embodiment, the modified document does not indicate whichcontent has been deleted. In yet another embodiment, deleted content maybe crossed-out and highlighted. In still yet another embodiment, contentthat the user has changed is not highlighted when viewed by the userbecause it is presumed that the user has read the modified content.

In one embodiment, an editor may rearrange content containers in thedocument without modifying any content within the content containers.The values in the table corresponding to the document are not changed.The rearranged content containers are not highlighted in the documentbecause the user has already read the content in the content containers.Merely moving a content container to a new location in the document isnot a significant enough modification to be brought to the user'sattention.

The author/editor identifier identifies the particular author/editor whocreated/modified the content in the corresponding content container. Inone embodiment, the author/editor identifier is used to highlightcontent in different colors such that particular additions/modificationsmay be associated with the corresponding author/editor. Thus, a readermay easily determine which author/editor added/modified the highlightedcontent based on the color associated with the author/editor.

FIG. 3 illustrates a shared document as it appears on a display beforeand after modifications are made to document content. Display 300 showsa “clean” version of a document (i.e., no highlighted content). A usermay be presented with a clean document version when the user accessesthe document from a server and no modifications have been made to thedocument since the last time that the user accessed the document. Theuser may then read and modify the document before closing and uploadingthe document to the server.

Display 350 shows a version of the document that includes highlightedcontent 360. Highlighted content 360 draws the attention of the user tothe document content that may have been modified since the last time theuser accessed the document, or to modified document content that theuser has not yet read. Highlighted content 360 includes text that hasbeen added to the shared document by another user. In one embodiment,highlighted content 360 may be displayed in a color that is visuallydistinct from the color of non-modified document content. In anotherembodiment, highlighted content 360 may be a background color thatdistinguishes the modified document content from the non-modifieddocument content. In yet another embodiment, tabs 370 that identifydocument pages where the highlighted content is located are presented inthe margin of the document. The user may select a tab and be brought tothe page that includes the highlighted content. For example, a user mayeasily determine that the document includes highlighted content on pages1, 5 and 9 because tabs 370 identify those pages in the margin of thedocument. In yet another embodiment, the user may access commands tonavigate highlighted content in order of appearance in the document orin chronological order based on when the content was modified. In stillanother embodiment, highlighted content 360 may be presented in a listsuch that a user can view all the modified portions of the documenttogether. In still yet another embodiment, highlighted content 360 maybe exported to a separate file where a user may access the modifieddocument portions.

FIG. 4 illustrates an operational flow diagram illustrating a processfor modifying content in a shared document. The process begins at astart block where a document is stored on a shared server.

Moving to block 400, the document is downloaded from the shared server.The document may be downloaded from any client connected to the server.The document may be downloaded by users who are authorized to edit thedocument. Proceeding to block 410, document content is modified by aneditor. Modified content may also include content that is added to thedocument by an author and content that is deleted from the document. Themodified content is associated with a unique identifier.

Advancing to block 420, an editor time stamp is associated with themodified document content. The editor time stamp is associated with thecorresponding modified document content via the unique identifier. Theeditor time stamp identifies the time when the document content wasmodified in, deleted from or added to the document. In one embodiment,the editor time stamp is associated with the unique identifier when theuser closes the document.

Transitioning to block 430, an author/editor identifier is associatedwith the modified content to identify who created/modified/deleted thedocument content. The author/editor identifier may be associated withthe corresponding modified document content via the unique identifier.Continuing to block 440, the document is uploaded to the shared server.Processing then terminates at an end block.

In one embodiment, the document and a table that includes the uniqueidentifier, the author/editor identifier, and the time stamp arecontinuously updated on the server. The document and the table may becontinuously updated by multiple users.

FIG. 5 illustrates an operational flow diagram illustrating a processfor highlighting modified content in a shared document. The processbegins at a start block where a shared document is stored on a server.

Moving to block 500, the document is downloaded from the shared server.The document may be downloaded from any client connected to the server.The document may be downloaded by users who are authorized to edit thedocument, or by users who are only authorized to read the document.

Proceeding to decision block 510, a determination is made whether anycontent in the document has been modified since the last time the useraccessed the document. Modified content includes document content thathas been changed, deleted or added. The document is associated with areader time stamp. The reader time stamp indicates the last time thatthe user accessed the document. The document is determined to includemodified content when the reader time stamp identifies a time that isearlier than the time identified by the editor time stamp. The readerand editor time stamps are associated by the unique identifier. If thedocument has not been modified since the last time the user accessed thedocument, processing continues at block 530. If the document has beenmodified since the last time the user accessed the document, processingcontinues at block 520.

Advancing to block 520, the modified content in the document ishighlighted. The highlighted content distinguishes the modified portionof the document from the rest of the document. In one embodiment, themodified document content is presented in a color that is visuallydistinct from the color of the non-modified content. In anotherembodiment, the modified document content is provided with a backgroundcolor that distinguishes the modified content from the non-modifieddocument content. In yet another embodiment, the highlighted content maybe presented in a list such that a user can view all the modifiedportions of the document together. In still another embodiment, thehighlighted content may be exported to a separate file where a user mayaccess the modified document portions.

Transitioning to block 530, the document is displayed such that the usermay view the document. In one embodiment, the document is displayed on amonitor of a computer. In another embodiment, the document is displayedwith tabs in the margin that identify the pages where the highlightedcontent is located. The user may select a tab to access thecorresponding page. In yet another embodiment, the document is displayedwith an author/editor identifier proximate the highlighted content toindicate who created/modified/deleted the highlighted content. In afurther embodiment, the author/editor identifier is used to highlightcontent in different colors such that particularadditions/modifications/crossed-out deletions may be associated with thecorresponding author/editor.

Continuing to decision block 540, a determination is made whether theuser has read all of the highlighted content. In one embodiment, thehighlighted content is determined to have been read by the user when thepage on which the highlighted content is located is displayed on amonitor of the user's computer. In another embodiment, a determinationis made that the user read the highlighted content when the actualmodified content is displayed to the user in its entirety. In yetanother embodiment, a user is determined to have read the highlightedcontent when the highlighted content is displayed to the user for apredetermined period of time. If the user has read all of thehighlighted content, processing continues at block 560. If the contenthas not read all of the highlighted content, processing continues atblock 550.

Moving to block 550, the relationship between the reader time stamp andthe associated highlighted content that has not been read by the user ismaintained. The reader time stamp identifies the time when the user lastaccessed the document. The relationship between the reader time stampand the associated unread, highlighted content ensures that the nexttime the user accesses the document the unread, modified content willappear as highlighted content.

Proceeding to block 560, a reader time stamp that identifies the currenttime is associated with the modified content that has been read by theuser. In one embodiment, the current reader time stamp identifies thetime when the user closes the document. Processing then terminates at anend block.

The above specification, examples and data provide a completedescription of the manufacture and use of the composition of theinvention. Since many embodiments of the invention can be made withoutdeparting from the spirit and scope of the invention, the inventionresides in the claims hereinafter appended.

1. A computer-implemented method for highlighting modified content in ashared document, comprising: downloading the document from a server to aclient, wherein the document comprises a content container; determiningif the content container has been modified since the document waspreviously downloaded to the client; when the content container has beenmodified, highlighting the modified content in the content container;displaying the document; determining whether the highlighted content hasbeen displayed to a user for at least a predetermined period of time;and when the highlighted content has not been displayed to a user for atleast the predetermined period of time, identifying the highlightedcontent as unread.
 2. The computer-implemented method of claim 1,further comprising: displaying the document with the highlighted contentthat was identified as unread when the document is subsequentlydownloaded.
 3. The computer-implemented method of claim 1, whereindetermining if the content container has been modified further comprisescomparing a reader time stamp associated with the content container atthe client and an editor time stamp associated with the contentcontainer at the server, wherein the reader time stamp indicates thetime when the document was previously downloaded to the client and theeditor time stamp indicates the time when the content container was lastmodified.
 4. The computer-implemented method of claim 1, whereindisplaying the document further comprises displaying the document withthe highlighted content and an author identifier, wherein the authoridentifier indicates the author who modified the highlighted content. 5.The computer-implemented method of claim 1, wherein highlighting themodified content further comprises displaying the modified content inthe content container such that the modified content is visuallydistinct from other portions of the document that have not been modifiedsince the document was previously downloaded.
 6. Thecomputer-implemented method of claim 1, further comprising displayingtabs in a margin of the document, wherein the tabs are associated withpages of the document that include highlighted content.
 7. Thecomputer-implemented method of claim 1, further comprising presentingthe highlighted content in a list.
 8. The computer-implemented method ofclaim 1, further comprising exporting the highlighted content to a file.9. The computer-implemented method of claim 1, wherein the predeterminedtime period is proportionate to the size of the content container.
 10. Asystem for highlighting modified content in a shared document,comprising: a server; an editor client coupled to the server, whereinthe editor client is arranged to: access the document from the server,and modify content in a content container the document; a reader clientcoupled to the server, wherein the reader client is arranged to accessthe document from the server; and a modification highlight module thatis located on one of: the reader client and the server, the modificationhighlight module being arranged to highlight the modified content in thecontent container when the document is accessed by the reader client,wherein the highlighted content indicates modifications that have beenmade to the content since the document was previously accessed by thereader client, wherein the document is displayed at the reader client, adetermination being made whether the highlighted content bas beendisplayed to a user for at least a predetermined period of time, andfurther wherein when the highlighted content has not been displayed to auser for at least the predetermined period of time, the highlightedcontent being identified as unread.
 11. The system of claim 10, whereinthe modification highlight module is further arranged to: display thedocument with the highlighted content that was identified as unread whenthe document is subsequently accessed by the reader client.
 12. Thesystem of claim 10, wherein the modification highlight module is furtherarranged to determine if the content container has been modified since aprevious document access by comparing a reader time stamp associatedwith the content container at the reader client and an editor time stampassociated with the content container at the server, wherein the readertime stamp indicates the time of the previous document access by thereader client and the editor time stamp indicates the time when thecontent container was last modified at the editor client.
 13. The systemof claim 10, wherein the modification highlight module is furtherarranged to display the document with the highlighted content and anassociated author identifier, wherein the author identifier indicatesthe author who modified the highlighted content.
 14. The system of claim10, wherein the modification highlight module highlights the modifiedcontent by displaying the modified content in the content container suchthat the modified content is visually distinct from other portions ofthe document that have not been modified since the document waspreviously accessed by the reader client.
 15. The system of claim 10,wherein the modification highlight module is further arranged to displaytabs in a margin of the document, wherein the tabs are associated withpages of the document that include highlighted content.
 16. The systemof claim 10, wherein the modification highlight module is furtherarranged to present the highlighted content in a list.
 17. The system ofclaim 10, wherein the predetermined time period is proportionate to thesize of the content container.
 18. A computer-readable medium havingcomputer-executable instructions for highlighting modified content in ashared document, comprising: accessing the document from a server,wherein the document comprises a content container; determining at aclient if the content container has been modified since the last timethe document was accessed from the server; when the content containerhas been modified, highlighting the modified content in the contentcontainer; displaying the document; determining if the highlightedcontent has been displayed to a user for at least a predetermined periodof time; when the highlighted content has not been displayed to a userfor at least the predetermined period of time, identifying thehighlighted content as unread; and displaying the document with thehighlighted content that is identified as unread when the document issubsequently accessed.
 19. The computer-readable medium of claim 18,wherein determining at the client if the content container has beenmodified further comprises comparing a reader time stamp associated withthe content container at the client and an editor time stamp associatedwith the content container at the server, wherein the reader time stampindicates the time of the last document access at the client and theeditor time stamp indicates the time when the content container was lastmodified.
 20. The computer-readable medium of claim 18, whereindisplaying the document further comprises displaying the document withan author identifier that is associated with the modified contentcontainer, wherein the author identifier indicates the author whomodified the highlighted content.
 21. The computer-readable medium ofclaim 18, wherein highlighting the modified content further comprisesdisplaying the modified content in the content container such that themodified content is visually distinct from the other portions of thedocument that have not been modified since the last document access. 22.The computer-readable medium of claim 18, further comprising displayingtabs in a margin of the document, wherein the tabs are associated withpages of the document that include highlighted content.
 23. Thecomputer-readable medium of claim 18, wherein the predetermined timeperiod is proportionate to the size of the content container.